This invention relates generally to methods and apparatus for analysis of vessel images, and more particularly to methods and apparatus for assisting medical care personnel such as radiologists in preparing measurements and reports for surgical planning from images derived from computed tomographic, MR, and 3D radiation imaging.
In at least some computed tomography (CT) imaging system configurations, an x-ray source projects a fan-shaped beam which is collimated to lie within an X-Y plane of a Cartesian coordinate system and generally referred to as the xe2x80x9cimaging planexe2x80x9d. The x-ray beam passes through the object being imaged, such as a patient. The beam, after being attenuated by the object, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is dependent upon the attenuation of the x-ray beam by the object. Each detector element of the array produces a separate electrical signal that is a measurement of the beam attenuation at the detector location. The attenuation measurements from all the detectors are acquired separately to produce a transmission profile.
In known third generation CT systems, the x-ray source and the detector array are rotated with a gantry within the imaging plane and around the object to be imaged so that the angle at which the x-ray beam intersects the object constantly changes. X-ray sources typically include x-ray tubes, which emit the x-ray beam at a focal spot. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator adjacent the collimator, and photodetectors adjacent the scintillator.
One of the important applications of computed tomographic (CT) imaging, as well as magnetic resonance (MR) imaging and 3-D x-ray imaging, is vascular analysis. X-ray quantification and analysis of vessel pathologies are important for radiologists who are called upon to assess stenosis or aneurysm parameters, quantify lengths, section sizes, angles, and related parameters. It would be desirable for these measurements to be performed in a consistent and repeatable manner so that referring physicians can rely upon them for surgical planning. Radiologists are also expected to provide thorough visual reports. For productivity reasons, as well as to reduce film costs, these visual reports need to be limited to only a small set of significant images.
3D visualization software provides a set of tools to perform length, angle or volume measurements and to visualize a volume in different ways, for example, using cross-sections, navigator or volume rendering. Known methods for quantification and analysis of vessel pathologies require an extensive array of tools to localize possible lesions, and then to perform measurements. Such methods are highly operator dependent, and require both time and software expertise. For example, a trained operator may need more than one hour to complete a single abdominal aorta aneurysm case. Even with trained operators given all the required time, results are not particularly reproducible and there are no consistent reporting frameworks. Furthermore, some measurements, such as true 3D-length measurement along vessels, cannot be performed using known manual tools. Because of these limitations, only a small number of sites are able to provide high-quality reports.
It would therefore be desirable to provide methods and apparatus assisting in the analysis of vessels and other structures that would assist operators in rapidly providing high-quality, consistent reports.
There is therefore provided, in one embodiment of the present invention, a method for analyzing tubular structures in a patient, including steps of: selecting a region of interest and a location within the region of interest from a displayed tube-shaped tree representative of a tubular structure in a patient; identifying a centerline of a structure within the tube-shaped tree within the region of interest; and displaying one or more views of the region of interest. The view or views are selected from at least a segmented 3-D view having the region of interest identified, a curved view of the selected branch, a reformatted view dependent upon the identified centerline, and a 3-D view dependent upon the identified centerline.
Embodiments of the present invention, including the embodiment described above, provide quick, easy, consistent, and full reports, without requiring excessive training or software expertise.